Exhaust valve for internal combustion engines



Jan. 20, 1959 A. SOURDILLON EXHAUST VALVE FOR INTERNAL-COMBUSTIONENGINES Filed June 27, 1957 Fig.2

lllllllm IIII///// INVENTOR Andre sourdillon W774, M Y/ML ATTORNEYS Uned States Patent EXHAUST VALVE FOR INTERNAL- COMBUSTION ENGINES AndrSourdillon, Saint CIoud, France, assignor to Societe Anonyme deVehicules Industriels et dEquipements Mecaniques (Savieni-Lrs), Paris,France, a company of France Application June 27, 1957, Serial No.668,385

Claims priority, application France June 30, 1956 1 Claim. or. 123-188)The invention relates to a valve for engines such as internal-combustionengines and Diesel engines, and more particularly to an exhaust valve.

After a certain amount of use, a deposit is formed between the valvestem and the guide thereof. This deposit is particularly harmful, sinceit may cause the valve stem to become jammed, or prevent it from workingproperly. The valve then does not close completely, which involvesdamage to its bearing surface and its seat by a blow-lamp effect.

The deposit produced can consist either of carbonaceous materials in thecase of ordinary petrol or oil fuel, or lead in thecase of petrolcontaining tetraethyl lead or similar compounds.

When the fuel contains tetra-ethyl lead for example, the deposit isformed chiefly by direct projection from the gases containing lead on tothe valve stem.

The invention avoids the formation of a deposit between the valve stemand the valve guide, and also prevents the end of the valve guide frombeing heated by the exhaust gases. The result of this is that thelubricating oil can be used satisfactorily right up to the end of thevalve guide.

According to the invention, the exhaust valve for engines comprising avalve head and a stem sliding in a guide is characterised in that thestem has an annular shoulder on the portion normally situated in theguide, said stem being of reduced diameter, above said shoulder andupwards to the outside of the guide, and the said shoulder passingoutside the valve guide when the valve head is in the fully liftedposition, the valve stem furthermore being fast with a cup whereof theconcave side is disposed towards the said guide.

Other features of the invention will be apparent from the followingdescription of methods of embodiment given by way of example, andillustrated in the accompanying drawings.

Figure 1 illustrates a valve according to the invention, the cup andpart of the valve guide being shown in section.

Figure 2 illustrates a further embodiment of a valve according to theinvention, the cup and part of the valve guide being shown in section,and the valve stem being partly cut away.

Figure 3 is an axial section of the cup fitted to the valve stemillustrated in Figure 2.

In Figure 1, the stem 1 of the valve 2 slides in a guide 3. The saidstern comprises a cup 4 whereof the concave side is disposed towards thevalve guide 3. The cup 4 covers the end of the guide.

In addition, the diameter of the valve stem' 1 is reduced in the region5, in the vicinity of the end of the guide 3, in order to remove anydeposit produced in the guide as soon as it forms. The shoulder 6 at thebase of the reduced portion serves to drive out of the guide 3 anyforeign body which might become lodged there.

2,869,532 Patented Jan. 20, 1959 F. ice

The cup 4, whereof the concave side is disposed towards the guide, canbe fitted to the valve stem 1 in various ways. It may be welded orbrazed on, or it may be attached mechanically to the stem, by screwingor crimping.

in Figures 2 and 3 as in the case of the preceding embodiment, the valvestem comprises a region 5 of reduced diameter, bounded at the base by ashoulder 6 which serves to drive out of the bore of the guide 3 anyforeign body which might become lodged there, especially a lead depositwhen the petrol contains tetra-ethyl lead or similar compounds.

This deposit of foreign matter is furthermore virtually non-existentbecause the cup 4 is so fitted that it always covers the top end of theguide 3. As may be seen in Figure 2, the lower edge 7 of the cup 4extends along the guide 3 beyond the shoulder 6. When the said shoulder6 has reached its highest position as shown by a dotted line in Figure2, the lower edge 7 of the cup still completely surrounds the end of theguide 3, and virtually prevents the gases capable of depositing leadfrom reaching the guide 3.

Thus if a small quantity of lead is deposited at the end of the guide 3,it is easily removed each time the shoulder 6 emerges.

In order that the cup 4 may be satisfactorily attached to the stem 1,the latter comprises a cylindrical bearing surface 8 with which isengaged a collar 9 fast with the cup 4. The collar 9 has a cylindricalbore 10 of a diameter corresponding to that of the cylindrical bearingsurface 8.

For attachment purposes, the collar 9 is pierced with orifices 11, andthe stem 1 is likewise pierced with orifices 12.

These orifices 11 and 12 are disposed opposite to one another, andfilled with welding material 13.

The invention allows the use of cups made of a material which isdifferent from that of the valve, and offers a good degree of resistanceto the exhaust gases. The cups can, for example, be made of a metal ofappreciably better quality than that of the valves. In addition, thecups can thus be made in the most suitable shapes for guiding the gasestowards the exhaust.

It has furthermore been found experimentally that valves fitted withcups according to the invention can be used for a very long time withvirtually no overhaul.

During supervised trials, it has been found for example that valves.fitted with cups according to the invention had their stems absolutelyintact after operating for a thousand hours, and that there was nodeposit of lead or similar materials at the end of the valve guide,while the stem and guide of a valve not comprising any cup arrangedaccording to the invention were fouled with deposits after the sameperiod of operation.

What I claim is:

An exhaust valve for internal combustion engines having a valve head ona valve stem sliding in a guide, an annular shoulder on the portion ofsaid stem normally situated in the guide, said stem being of reduceddiameter above said shoulder extending above the end of the guide,said'shoulder passing out of the guide when the valve head is in itsfully lifted position, and a concave cup fixed to said stem with itsconcave side disposed towards and surrounding the guide, said shoulderbeing situated within said cup and the end of said guide being situatedwithin said cup when the valve is in its fully lifted position.

(References on following page) Refer'enes Cited in the file of thispatent UNITED STATES PATENTS Smith Apr. 24, 1906 Dahlgren June 19, 19175 Shepherd Nov. 20, 1923 De'vos-et a1. Mar. 23;, 1926

